public static void Main() {
Console.WriteLine("Enter your code:");
var inputCode = Console.ReadLine();
VerifyInputCode(inputCode);
public static void VerifyInputCode(string inputCode) {
while (inputCode.Length != 4) {
Console.WriteLine("Invalid code.");
Console.Write("Code must be 4 digits.");
inputCode = Console.ReadLine();
if (Convert.ToInt32(inputCode) == secretCode) {
Console.WriteLine("Congtrazzz!! you got it. :)");
Console.WriteLine("Opps!!! Wrong Code");
Console.Write("Reenter Code.");
inputCode = Console.ReadLine();